1. Technical Field
The present invention relates to polishing techniques and, particularly, to an abrasive composite for use in a polishing process/apparatus and a method for making the abrasive composite.
2. Discussion of the Related Art
Nowadays, a chemical mechanical polishing (hereinafter, CMP) has been widely used for polishing various elements such as semiconductor wafers, optical elements, and ceramic articles.
During a CMP process, outer portions of a workpiece are initially removed therefrom, due to a physical reaction, such as abrasion, and a chemical reaction, such as oxidation and/or chelation. As such, the surface of the workpiece is polished (i.e., smoothed). Typically, an abrasive composite is incorporated on and/or in a polishing faceplate capable of contacting the surface of the workpiece in order to achieve the removal of material and thereby smooth of the surface.
A conventional abrasive composite includes a binder (i.e., a matrix) and a number of abrasive particles distributed therein. The abrasive particles typically include ceramic particles having an average grain size in the range from 0.1 to 0.4 microns. At least 50 percent by weight of the ceramic particles are comprised of a material selected from alumina, ceria, silica, or a combination thereof. Nevertheless, the ceramic particles tend to have a lower wear resistance. In addition, the ceramic particles generally have irregular, roughened outer surfaces. Due to the irregular, roughened surfaces, the surface to be treated of the workpiece may potentially be scratched, thereby causing defects on the workpiece.
What is needed, therefore, is an abrasive composite that has excellent mechanical properties, has a high wear resistance, and is capable of minimizing the risk of scratching a surface of a workpiece.
What is also needed, therefore, is a polishing apparatus using that abrasive composite.
What is also needed, therefore, is a method for making that abrasive composite.